RU2801380C1 - Catalyst and method for catalytic oxidation-deoxygenation of gas containing unsaturated hydrocarbon - Google Patents

Abstract

FIELD: gas treatment.

SUBSTANCE: catalyst for the oxidation-deoxygenation of an unsaturated hydrocarbon-containing gas containing a carrier, as well as an active component, the first component is a shared agent and the second component is a shared agent deposited on the carrier, where the active component is one or more components selected from the group consisting of oxides of Pt, Pd, Ru, Rh, Ag and Ir; the first component - shared agent includes one or more elements selected from the group consisting of rare earth metal, metal of group IVB and metal of group VIII, and the second component - shared agent includes one or more elements selected from the group consisting of alkali metal and alkaline earth metal; in the radial direction from the core of the carrier to the outer surface of the carrier, the content of said active component gradually increases and then gradually decreases to form a peak-shaped distribution, the content of said first component - a shared agent gradually increases and then gradually decreases to form a distribution in the form of a peak, the content of the said second component - a shared agent gradually increases, and the peak value of the content of the said active component is 0.2 wt.% or more; the specified active ingredient is contained in an amount of 0.05-2 wt.% in terms of the metal element, the specified first component - a shared agent is contained in an amount of 0.1-3 wt.% in terms of oxide, and the specified second component - a shared agent is contained in an amount of 1-7 wt.% in terms of oxide, based on the dry weight of the catalyst. A method for catalytic oxidation-deoxygenation of a gas containing an unsaturated hydrocarbon, including an unsaturated hydrocarbon and oxygen, is described, including bringing the gas containing an unsaturated hydrocarbon into contact with the catalyst described above under the following contacting conditions: the gas containing an unsaturated hydrocarbon has an hourly space velocity of 200-50,000 h^-1, a pressure of 0.01-20 MPa, a linear velocity of 0.02-10 m/s, and the pressure product at linear speed is 0.1-5 MPa⋅ m/s.

EFFECT: reduced formation of carbon deposits in the process of catalytic oxidation-deoxygenation.

13 cl, 16 dwg, 3 tbl, 4 ex

Description

Cross-reference to related applications

The application claims priority over the filing date of Chinese Patent Application No. 202010087815.3, which is specifically and in its entirety incorporated herein by reference.

Technical field

The present invention relates to the technical field of the chemical treatment of residual gases and, in particular, to a catalyst and a method for the catalytic oxidation-deoxygenation of an unsaturated hydrocarbon-containing gas using a catalyst.

State of the art

Oxygen-containing organic hydrocarbon gas or tail gas is a common gas in the course of current chemical production, storage and transportation processes, such as organic tail gas in oxidation and peroxidation processes, tail gas of an oil storage system and landfill gas, it often causes an explosion hazard due to high oxygen content; and industry standard SH 3009-2013 "Specifications for the design of a combustible gas removal system in petrochemical engineering", ed. 5.3.1 states that "combustible gas with an oxygen content of more than 2% by volume (vol.%)" should not be discharged into the combustible gas exhaust system of the entire plant, such as a flare, an incinerator, etc. Thus, deoxygenation (removal of oxygen) of the oxygenated organic gas or tail gas is required to reduce the risk of explosion, recycle the organic gas, or ensure that the oxygenated organic tail gas meets emission requirements. As for the epoxy propane production equipment, including the conventional chlorohydrin epoxy propane production equipment and the hydrogen peroxide epoxy propane production equipment used in recent years, the oxygen content of the residual propylene gas ranges from 0.2% to 8%, according to specifications require that the gas is not vented to a combustible gas discharge system, the oxygen content must be reduced to less than 0.5% for emissions, or the oxygen content must be further reduced to 0.1% or lower to facilitate recycling.

The currently available deoxygenation technologies mainly consist of pressure swing physical adsorption deoxygenation, chemical adsorption deoxygenation, activated carbon combustion deoxygenation, catalytic combustion deoxygenation and catalytic oxidation-deoxygenation, while pressure swing physical adsorption deoxygenation and chemical adsorption deoxygenation have small loadings. and are suitable for removing traces of oxygen; deoxygenation by burning activated carbon requires high temperature and high energy consumption; catalytic combustion deoxygenation technologies generally require the addition of a reducing gas such as N, and separating the reducing gas becomes a difficult problem; current catalytic oxidation-deoxygenation technologies are mainly for methane-containing gases such as coal seam gas and waste gas, while olefin deoxygenation technologies (e.g. ethylene, propylene) are only suitable for removing trace oxygen at the ppm level, and catalytic oxidation technologies - deoxygenation of olefins (e.g. ethylene and propylene) and higher oxygen alkynes are unknown, while olefins and alkynes tend to form carbon deposits on the catalyst surface at a certain temperature, and for them the requirements for catalytic oxidation-deoxygenation technologies differ from requirements for catalytic oxidation-deoxygenation technologies for methane.

BRIEF DESCRIPTION OF THE INVENTION The present invention is directed to providing a catalyst and a method for the catalytic oxidation-deoxygenation of an unsaturated hydrocarbon-containing gas using a catalyst. The use of the catalyst of the present invention can reduce the formation of carbon deposits, and the catalytic oxidation-deoxygenation method of the present invention eliminates the need to add a reducing gas such as H ₂ , allows hydrocarbons to react directly with oxygen to form CO ₂ and H ₂ O, achieves deoxygenation of the hydrocarbon containing residual gas, and the reaction device is safe, environmentally friendly and energy efficient.

The present invention provides a catalyst containing a carrier, as well as an active component, the first component is a shared agent and the second component is a shared agent supported on a carrier, where the active component is one or more components selected from the group consisting of oxides of Pt , Pd, Ru, Rh, Ag and Ir; the first component, the shared agent, comprises one or more elements selected from the group consisting of a rare earth metal, a Group IVB metal, and a Group VIII metal; and the second component - a shared agent includes one or more elements selected from the group consisting of an alkali metal and an alkaline earth metal;

in the radial direction from the core of the carrier to the outer surface of the carrier, the content of the specified active component gradually increases and then gradually decreases to form a distribution in the form of a peak, the content of the specified first component - the joint agent gradually increases and then gradually decreases to form a distribution in the form of a peak, the content of the specified second component - shared agent gradually increases, and the peak value of the content of the specified active component is 0.2 mass. % or more;

the specified active ingredient is contained in an amount of 0.05-2 wt. % in terms of the metal element, the specified first component - a shared agent is contained in an amount of 0.1-3 wt. % in terms of oxide, and the specified second component - a shared agent is contained in an amount of 1-7 wt. % in terms of oxide, based on the dry weight of the catalyst.

Preferably, the mass percentage of carbon deposits y for the catalyst, measured in a propylene atmosphere at a pressure of 0.6 MPa and a temperature of 573.15 K, has the following characteristics:

y=0.9y1 - 1.1y1, y1=(-0.0029+0.3748×t ^1.3013 )/100

where t: reaction time, in the range of 100-2000 hours;

and before measurement, the catalyst has a mass percentage of carbon deposits of 0.2% or less.

Preferably, the amount q of adsorbed oxygen at saturation for the catalyst after reduction with hydrogen at normal pressure and temperature of 473.15 K has the following characteristics:

q=0.8q1 - 1.2q1, q1=a+b×T ^c +d×T ^e

q: amount of adsorbed oxygen at saturation, ml/g;

T: adsorption temperature, in the range 323.15-623.15 K;

a=-0.0685; b=7.016×10 ^-6 ; c=2.06; d=-5.83×10 ^-8 ; e=2.76.

Preferably, the first shared agent component comprises one or more elements selected from the group consisting of a Group IVB metal and a Group VIII metal, and the second shared agent component comprises an alkali metal; more preferably, the first shared agent component is one or more selected from the group consisting of ferric oxide, cobalt oxide, nickel oxide, and titanium oxide, and the second shared agent component is sodium oxide; and even more preferably, the weight ratio of the first component - shared agent to the second component - shared agent is 1:20-220, preferably 1:60-200.

Preferably, the catalyst has a specific surface area of 100-260 m ² /g and a pore volume of 0.2-0.7 cm ³ /g; mesopores with a pore size of more than 2 nm and 50 nm or less account for 2-40% of the total pore volume, and macropores with a pore size of more than 50 nm and 200 nm or less account for 50-90% of the total pore volume.

Preferably, the carrier is one or more carriers selected from the group consisting of alumina, silica, titanium dioxide, molecular sieves and carbon nanotubes.

Preferably, the content of the active component having a dispersed size of less than 10 nm is 80 wt. % or more of the total active ingredient.

The present invention also provides a method for catalytically oxidizing-deoxygenating an unsaturated hydrocarbon-containing gas comprising an unsaturated hydrocarbon and oxygen, comprising contacting the unsaturated hydrocarbon-containing gas with a catalyst and performing a catalytic oxidation process to remove oxygen from the unsaturated hydrocarbon-containing gas;

where the catalyst is said catalyst of the present invention, the contacting conditions include that the unsaturated hydrocarbon-containing gas has an hourly space velocity of 200-50000 h ^-1 , preferably 200-20000 h ^-1 , pressure of 0.01-20 MPa, linear speed is 0.02-10 m/s, and the product of pressure and linear velocity is 0.1-5 MPa⋅m/s.

Preferably, the unsaturated hydrocarbon-containing gas has an hourly space velocity of 500-20,000 h ^-1 , preferably 500-10,000 h ^-1 , a pressure of 0.4-10 MPa, a linear velocity of 0.02-5 m/s, and the product of pressure and linear velocity is 0.2-5 MPa⋅m/s.

Preferably, the method further comprises the following steps:

(1) lowering the temperature of the gas obtained from the catalytic oxidation reaction and separating the gas and liquid;

(2) separating the gas phase resulting from the gas-liquid separation to obtain at least a portion of the unsaturated hydrocarbons.

Preferably, the method further comprises, prior to the catalytic oxidation, exchanging heat between the unsaturated hydrocarbon-containing gas and the gas resulting from the catalytic oxidation reaction.

Preferably, the unsaturated hydrocarbons are unsaturated hydrocarbons with C4 or less carbon atoms, preferably one or more unsaturated hydrocarbons selected from the group consisting of ethylene, propylene, 1-butene, 2-butene, isobutylene, 1,3-butadiene, acetylene, propyne, 1-butyne and 2-butyne.

Preferably, the reactor inlet temperature is 60-400°C, the reactor outlet temperature is 100-600°C.

Preferably, the reactor inlet temperature is 100-380°C, the reactor outlet temperature is 150-550°C.

Preferably, said catalytic oxidation reaction is carried out in a fixed bed reactor.

Preferably, the method further includes a safety control process including a blocking - triggering an alarm step, wherein the blocking - triggering an alarm step includes determining whether the reactor inlet temperature, the reactor outlet temperature, the oxygen content in the feed gas, the content oxygen in the residual gas of the corresponding alarm value or blocking value, and the implementation of emergency blocking control.

Preferably, the lower reactor inlet temperature alarm value is 60-90°C, the lower reactor inlet temperature shutdown value is 40-60°C, the reactor outlet upper temperature alarm value is 580-610°C, the upper reactor temperature at the outlet of the reactor is 610-650°C, the upper emergency value of the oxygen content in the feed gas is 7.5-8.5 vol. %, the upper blocking value of the oxygen content in the supplied gas is 8.5-10 vol. %, and the upper emergency value of the oxygen content in the residual gas is 0.2-0.3 vol. %.

Preferably, the unsaturated hydrocarbon-containing gas contains 0.2-8% oxygen and 5-99% unsaturated hydrocarbons, based on volume percent concentration.

The catalyst of the present invention can reduce the formation of carbon deposits. In addition, the catalytic oxidation-deoxygenation process of the present invention eliminates the need to add a reducing gas such as H ₂ , allows the (unsaturated) hydrocarbons of a gas containing unsaturated hydrocarbons to react directly with oxygen to form CO ₂ and H ₂ O, achieves the purpose of deoxygenating a hydrocarbon-containing residual gas, and can suppress the formation of carbon deposits on the surface of the catalyst and the formation of by-product CO, and also shows high tolerance to fluctuations in the oxygen content of the feed gas.

Brief description of the drawings

In FIG. 1 is a flow diagram of a process for the catalytic oxidation-deoxygenation of an unsaturated hydrocarbon-containing gas according to a specific embodiment of the present invention;

in fig. 2 shows an SEM image of the catalytic oxidation catalyst obtained in Production Example 1;

in fig. 3 is a graph showing the content distribution of ingredients after impregnation in Production Example 1;

in fig. 4 is a graph showing the content distribution of ingredients after impregnation in Production Example 2;

in fig. 5 is a graph showing the content distribution of ingredients after impregnation in Production Example 3;

in fig. 6 is a graph showing the content distribution of ingredients after impregnation in Production Example 4;

in fig. 7 shows an SEM image of the catalytic oxidation catalyst obtained in Comparative Production Example 1;

in fig. 8 is a graph showing the content distribution of ingredients after impregnation in Comparative Production Example 1;

in fig. 9 shows an SEM image of the catalytic oxidation catalyst obtained in Comparative Production Example 2;

in fig. 10 is a graph showing the content distribution of ingredients after impregnation in Comparative Production Example 2;

in fig. 11 shows an SEM image of the catalytic oxidation catalyst obtained in Comparative Production Example 3;

in fig. 12 is a graph showing the content distribution of ingredients after impregnation in Comparative Production Example 3;

in fig. 13 shows an SEM image of the catalytic oxidation catalyst obtained in Comparative Production Example 4;

in fig. 14 is a graph showing the content distribution of ingredients after impregnation in Comparative Production Example 4;

in fig. 15 shows an SEM image of the catalytic oxidation catalyst obtained in Comparative Production Example 5;

in fig. 16 is a graph showing the content distribution of ingredients after impregnation in Comparative Production Example 5.

Description of reference symbols

1. Heat exchange unit

2. Heating block

3. Deoxygenation reaction block

4. Temperature reduction unit

5. Gas-liquid separation unit

6. Compressor

7. Non-condensable gas separation column

A. Gas containing unsaturated hydrocarbon

8. Deoxygenated gas

C. Waste Fluid

D. Non-condensable gas

E. Unsaturated hydrocarbons

F. Combustible gas exhaust system

O.A. Residual oxygen analysis unit.

Detailed description of the invention

Unless otherwise indicated in the present description, the concentration "%" of the gas refers to "vol. %", the term "space velocity" refers to "hourly space velocity" and pressure refers to absolute pressure.

In accordance with the first aspect of the present invention, there is provided a catalyst containing a carrier, as well as an active component, the first component is a shared agent and the second component is a shared agent supported on a carrier, where the active component is one or more components selected from the group , consisting of oxides of Pt, Pd, Ru, Rh, Ag and Ir;

in the radial direction from the core of the carrier to the outer surface of the carrier, the content of the specified active component gradually increases and then gradually decreases to form a distribution in the form of a peak, the content of the specified first component - the joint agent gradually increases and then gradually decreases to form a distribution in the form of a peak, the content of the specified second component - shared agent gradually increases, and the peak value of the content of the specified active component is 0.2 mass. % or more;

the first component, the shared agent, comprises one or more elements selected from the group consisting of a rare earth metal, a Group IVB metal, and a Group VIII metal; and the second component - a shared agent includes one or more elements selected from the group consisting of an alkali metal and an alkaline earth metal; the active ingredient is contained in an amount of 0.05-2 wt. % in terms of the metal element, the first component - a shared agent is contained in an amount of 0.1-3 wt. % in terms of oxide, and the specified second component - a shared agent is contained in an amount of 1-7 wt. % in terms of oxide based on the dry weight of the catalyst.

According to the present invention, preferably, the mass percentage of carbon deposits y for the catalyst, measured in a propylene atmosphere at a pressure of 0.6 MPa and a temperature of 573.15 K, has the following characteristics:

y=0.9y1 - 1.ly1, y1=(-0.0029+0.3748×t ^0.3013 )/100

where t: reaction time, in the range of 100-2000 hours;

and before measurement, the catalyst has a mass percentage of carbon deposits of 0.2% or less.

According to the present invention, when the mass percentage of carbon deposit of the catalyst is 0.2% or less before measurement, the catalyst can be treated by the catalyst regeneration method commonly used in the art so that the mass percentage of carbon deposit of the catalyst meets the requirement of the present invention before testing. ; and as a regeneration method, the catalyst may, for example, be subjected to calcination.

In the present description, "dry weight of the catalyst" refers to the weight of the catalyst, dried to constant weight at 200°C.

According to the present invention, preferably, the amount q of adsorbed oxygen at saturation for the catalyst after reduction with hydrogen at normal pressure and temperature of 473.15 K has the following characteristics:

q=0.8q1 - 1.2q1, q1=a+b×T ^c +d×T

q: amount of adsorbed oxygen at saturation, ml/g;

T: adsorption temperature, in the range 323.15-623.15 K;

a=-0.0685; b=7.016×10 ^-6 ; c=2.06; d=-5.83×10 ^-8 ; e=2.76.

According to the present invention, the catalyst includes a carrier, as well as an active component, the first component is a shared agent and the second component is a shared agent deposited on the carrier; the active component is one or more noble metal elements selected from the group consisting of oxides of Pt, Pd, Ru, Rh, Ag and Ir; the first component, the shared agent, comprises one or more elements selected from the group consisting of a rare earth metal, a Group IVB metal, and a Group VIII metal; and the second component - a shared agent includes one or more elements selected from the group consisting of an alkali metal and an alkaline earth metal; preferably, the first component, the shared agent, comprises one or more elements selected from the group consisting of a Group IVB metal and a Group VIII metal, and the second component, the shared agent, comprises an alkali metal; more preferably, the first shared agent component is one or more selected from the group consisting of ferric oxide, cobalt oxide, nickel oxide, and titanium oxide, and the second shared agent component is sodium oxide; even more preferably, the weight ratio of the first component - shared agent to the second component - shared agent is 1:20-220, preferably 1:60-200.

Preferably, the active ingredient is contained in an amount of 0.1-1 wt. % in terms of a metal element, the first component - a shared agent is contained in an amount of 0.1-1 wt. % in terms of oxide, and the second component - a shared agent is contained in an amount of 3-8 wt. % in terms of oxide, based on the dry weight of the catalyst; more preferably, the active ingredient is contained in an amount of 0.2-0.5 wt. % in terms of the metal element, the first component - a shared agent is contained in an amount of 0.1-0.7 wt. % in terms of oxide, and the second component - a shared agent is contained in an amount of 4-6 wt. % in terms of oxide, based on the dry weight of the catalyst.

Preferably, in the radial direction from the core of the carrier to the outer surface of the carrier, the content of the active component gradually increases and then gradually decreases to form a distribution in the form of a peak, the content of the first component - the co-agent gradually increases and then gradually decreases to form a distribution in the form of a peak, the content of the second component - the shared agent gradually increases, and the peak value of the content of the active component is 0.2-0.4 wt. %; more preferably, in the radial direction from the core of the carrier to the outer surface of the carrier, the content of the active component gradually increases and then gradually decreases to form a distribution in the form of a peak, the content of the first component - the co-agent gradually increases and then gradually decreases to form a distribution in the form of a peak , the content of the second component - the shared agent gradually increases, and the peak value of the content of the active component is 0.2-0.35 wt. %; more preferably, in the radial direction from the core of the carrier to the outer surface of the carrier, the content of the active component gradually increases and then gradually decreases to form a distribution in the form of a peak, the content of the first component - the co-agent gradually increases and then gradually decreases to form a distribution in the form of a peak , the content of the second component - the shared agent gradually increases, and the peak value of the content of the active component is 0.2-0.3 wt. %.

In the present invention, the carrier may be a substance or various substances that can be used as catalyst carrier(s), preferably, in order to further reduce carbon deposits, the carrier is one or more carriers selected from the group consisting of alumina , silicon dioxide, titanium dioxide, molecular sieves and carbon nanotubes, more preferably alumina, silicon dioxide, and the like.

Preferably, in order to further reduce carbon deposits, the catalyst has a specific surface area of 100-260 m ² /g, more preferably 120-220 m ² /g, and a pore volume of 0.2-0.7 cm ³ /g, more preferably 0. 3-0.6 cm ³ /g; mesopores with a pore size of more than 2 nm and 50 nm or less make up 2-40%, more preferably 5-30% of the total pore volume, and macropores with a pore size of more than 50 nm and 200 nm or less make up 50-90%, more preferably 60-80% of the total pore volume.

Unless otherwise stated herein, specific surface area and pore volume are measured using the BET (Brunauer-Emmett-Teller) method, and pore distribution is determined using the BJH (Barrett-Joyner-Halenda) method.

Preferably, to further reduce carbon deposits, the active component having a dispersed size of less than 10 nm is contained in an amount of 80 wt. % or more of the total active ingredient; more preferably, the active component having a disperse size of less than 10 nm is contained in an amount of 85 wt. % or more, even more preferably 90 wt. % or more, even more preferably 95 wt. % or more of the total active ingredient; wherein the active size and corresponding content is measured by STEM (scanning transmission electron microscopy) scan analysis.

As the production method of the catalyst of the present invention, an impregnation method such as saturation impregnation, equivalent volume impregnation is preferably used. The sequence of impregnation of the active component and the components - joint agents is not particularly limited, the components can be impregnated and applied simultaneously or impregnated and applied separately; in particular, the solution containing the active ingredient and the co-agent components can be contacted with a carrier followed by a drying and calcination process; or the solution containing the active ingredient or the co-agent component may be contacted with the carrier followed by a drying and calcination process, after which the solution containing the co-agent component or the active ingredient is contacted with the carrier followed by a drying and calcination process, as a result whereby a catalyst is obtained containing an active component and components - shared agents. Preferably, the drying temperature may be 80-150° C. and the time may be 10-100 minutes; the calcination temperature may be 500-600° C. and the time may be 30-300 minutes.

In a preferred embodiment of the present invention, the catalyst is prepared according to the following steps.

1) Carrying out a first impregnation of an alumina carrier with an equivalent volume of an aqueous solution containing the active ingredient at pH 3-4, followed by a first drying process;

2) carrying out a second impregnation of the alumina obtained in step (1) with an equivalent volume of an aqueous solution containing the first component - a shared agent, in the presence of an organic complexing agent at pH 8-10, followed by a second drying process;

3) carrying out a third impregnation of the alumina carrier obtained in step (2) with an equivalent volume of an aqueous solution containing the second component, a shared agent, at pH 9-11, followed by a third drying and calcination process.

Preferably, said first drying process is carried out at a temperature of 70-90°C for 100-200 minutes.

Preferably, said second drying process is carried out at a temperature of 110-150°C for 50-150 minutes.

Preferably, said third drying process is carried out at a temperature of 160-190°C for 50-150 minutes.

Preferably, the calcination temperature is 450-550° C. and the calcination time is 2-10 hours.

The amount of each component in each of the above steps is not particularly limited, as long as the content of the components in the resulting catalyst falls within the scope of the present invention.

The organic complexing agent may be, for example, one or more agents selected from the group consisting of ethanolamine, diethanolamine and triethanolamine.

The amount of organic complexing agent is not particularly limited and may be, for example, 1-3 mass. % impregnating solution.

According to a second aspect of the present invention, there is provided a method for catalytically oxidizing-deoxygenating an unsaturated hydrocarbon-containing gas comprising an unsaturated hydrocarbon and oxygen, the method comprising contacting the unsaturated hydrocarbon-containing gas with a catalyst and performing a catalytic oxidation process to remove oxygen from the unsaturated hydrocarbon-containing gas; where the catalyst is said catalyst of the present invention, the contacting conditions include that the unsaturated hydrocarbon-containing gas has an hourly space velocity of 200-50,000 h ^-1 , a pressure of 0.01-20 MPa, a linear velocity of 0.02-10 m/ s, and the product of pressure and linear velocity is 0.1-5 MPa⋅m/s.

Preferably, the contacting conditions include that the unsaturated hydrocarbon containing has an hourly space velocity of 200-20000 h ^-1 , a pressure of 0.1-20 MPa, a linear velocity of 0.02-10 m/s, and the product of pressure and linear velocity is 0.1-5 MPa⋅m/s.

More preferably, the unsaturated hydrocarbon-containing gas has an hourly space velocity of 500-20,000 h ^-1 , a pressure of 0.4-10 MPa, a linear velocity of 0.02-5 m/s, and a product of pressure and linear velocity of 0.2-5 MPa ⋅m/s.

More preferably, the unsaturated hydrocarbon-containing gas has an hourly space velocity of 500-10,000 h ^-1 , a pressure of 0.4-10 MPa, a linear velocity of 0.02-5 m/s, and a product of pressure and linear velocity of 0.2-5 MPa ⋅m/s.

Even more preferably, the unsaturated hydrocarbon-containing gas has an hourly space velocity of 500-10000 h ^-1 , a pressure of 0.4-10 MPa, a linear velocity of 0.02-5 m/s, and a pressure-linear velocity product of 0.2-2 MPa⋅m/s.

In the present specification, the linear velocity of an unsaturated hydrocarbon-containing gas refers to the gas flow rate in m/s and is obtained by dividing the flow rate (m ³ /s) by the cross-sectional area (m ² ).

In accordance with the present invention, unsaturated hydrocarbons are unsaturated hydrocarbons with C4 carbon atoms or less, preferably one or more unsaturated hydrocarbons selected from the group consisting of ethylene, propylene, 1-butene, 2-butene, isobutylene, 1, 3-butadiene, acetylene, propyne, 1-butane and 2-butyne.

In the present invention, the unsaturated hydrocarbon-containing gas may contain unsaturated hydrocarbon and oxygen, preferably in volume percent concentration, the unsaturated hydrocarbon-containing gas comprises 0.2-8% oxygen and 5-99% unsaturated hydrocarbon; more preferably, the unsaturated hydrocarbon-containing gas contains 0.5-5% oxygen, 20-95% unsaturated hydrocarbon, and the rest is saturated hydrocarbons or other inert gases that do not significantly adversely affect the catalytic oxidation reaction, such as nitrogen gas, dioxide carbon, hydrogen gas and other organic gases. After the catalytic deoxygenation treatment of the present invention, the gas phase obtained from gas-liquid separation contains oxygen gas at a volume percentage concentration of less than 0.2%, CO selectivity is less than 0.5%, and CO ₂ selectivity is more than 98%. . The method of the present invention is particularly suitable for treating propylene tail gas from an epoxy propane machine, such as propylene tail gas from a chlorohydrin epoxy propane machine and/or an epoxy propane machine using a hydrogen peroxide process.

According to the present invention, the catalyst enables the oxidation reaction of an unsaturated hydrocarbon in an unsaturated hydrocarbon-containing gas with oxygen gas to achieve the purpose of removing oxygen. Preferably, the unsaturated hydrocarbon is completely oxidized according to the reaction formula: C _X H _Y +O ₂ → CO ₂ +H ₂ O, where C _x H _y is an unsaturated hydrocarbon.

By using the catalyst of the present invention, most of the oxygen gas can carry out a complete oxidation reaction with unsaturated hydrocarbons, thereby producing the desired deoxygenation effects and preventing carbon deposits.

With regard to the conditions of the catalytic oxidation-deoxygenation process of the present invention, preferably, the reactor inlet temperature is 60-400°C, the reactor outlet temperature is 100-600°C; more preferably, the reactor inlet temperature is 100-380°C, the reactor outlet temperature is 150-550°C. The temperature at the outlet of the reactor is usually 50-270°C, preferably 80-200°C, higher than the temperature at the inlet to the reactor. By carrying out the catalytic oxidation-deoxygenation reaction under the above conditions, the deoxygenation efficiency can be further improved. Preferably, the catalytic oxidation reaction is carried out in a fixed bed reactor, more preferably in an adiabatic fixed bed reactor.

In accordance with the present invention, preferably, the method further comprises the following steps:

(1) lowering the temperature of the gas obtained from the catalytic oxidation reaction and performing gas-liquid separation;

(2) separating the gas phase resulting from the separation of gas and liquid to obtain at least a portion of unsaturated hydrocarbons.

By subjecting the gases resulting from the catalytic oxidation reaction to the above operations, pure unsaturated hydrocarbons can be recovered.

According to the present invention, in order to fully utilize the heat generated by the catalytic oxidation reaction, preferably, the method further comprises exchanging heat between the unsaturated hydrocarbon-containing gas and the gas produced by the catalytic oxidation reaction before the catalytic oxidation. In addition, in order to achieve the gas-liquid separation effect, it is more preferable to cool the gas obtained by the catalytic oxidation reaction to a temperature below 40°C (for example, 20 to 30°C), and then carry out the gas-liquid separation.

According to another embodiment of the present invention, the method for catalytic oxidation-deoxygenation of an unsaturated hydrocarbon-containing gas provided by the present invention further includes a safety monitoring step including a lock-out alarm step, wherein the lock-out alarm trigger step includes determining whether the reactor inlet temperature, the reactor outlet temperature, the oxygen content of the feed gas, the oxygen content of the residual gas of the corresponding alarm value or blocking value, and the implementation of the following emergency blocking control.

The stage of blocking - triggering the alarm includes: (1) setting the lower alarm value of the temperature at the inlet to the reactor, turning on the power of the heating block 2 after the alarm; setting the lower blocking temperature value at the inlet to the reactor, closing the inlet shut-off valve and venting gas into the flare after blocking-startup; (2) setting an upper reactor outlet temperature alarm, reducing the power of the heating unit 2 and increasing the volume of gas circulation after the alarm; setting the upper blocking temperature at the reactor outlet, stopping the supply of the reaction mixture, increasing the cooling capacity of the reactor cooling system, filling the reactor with nitrogen gas to dilute and cool the gas after blocking-startup; (3) setting the upper alarm value of the oxygen content in the supply gas, adjusting the volume of circulating gas after the alarm; setting an upper lockout value for the oxygen content of the feed gas, filling the reactor with nitrogen gas to dilute the oxygen content to a safe level, and then performing the deoxygenation reaction after the block-start, and (4) setting an upper alarm value for the oxygen content in the residual gas after the deoxygenation process, adjusting the temperature at the reactor inlet after the alarm.

Preferably, the lower reactor inlet temperature alarm value is 60-90°C, the lower reactor inlet temperature shutdown value is 40-60°C, the reactor outlet upper temperature alarm value is 580-610°C, the upper reactor temperature at the outlet of the reactor is 610-650°C, the upper emergency value of the oxygen content in the feed gas is 7.5-8.5 vol. %, the upper blocking value of the oxygen content in the supplied gas is 8.5-10 vol. %, and the upper emergency value of the oxygen content in the residual gas is 0.2-0.3 vol. %. In particular, the lower reactor inlet temperature alarm value may be 80°С, the reactor inlet lower temperature shutdown value may be 50°С, the reactor outlet temperature upper alarm value may be 600°С, the the outlet of the reactor can be 630°C, the upper emergency value of the oxygen content in the feed gas can be 8 vol. %, the upper blocking value of the oxygen content in the supplied gas can be 9 vol. %, and the upper emergency value of the oxygen content in the residual gas can be 0.25 vol. %.

The present invention also provides a plant for catalytic oxidation-deoxygenation of an unsaturated hydrocarbon-containing gas, including a heat exchange unit, a heating unit, a deoxygenation reaction unit, a temperature reduction unit, a gas-liquid separation unit, and a hydrocarbon separation unit; wherein the heat exchange unit is used for exchanging heat between the unsaturated hydrocarbon-containing gas and the gas treated in the deoxygenation reaction unit to heat the unsaturated hydrocarbon-containing gas while cooling the gas treated in the deoxygenation reaction unit; the heating unit is used to additionally heat the unsaturated hydrocarbon-containing gas subjected to heat exchange in the heat exchange unit; the deoxygenation reaction unit is used for catalytically oxidizing the unsaturated hydrocarbon-containing gas obtained from the heating unit to remove oxygen from the unsaturated hydrocarbon-containing gas; the temperature reduction unit is connected to the heat exchange unit for additional cooling of the gas treated in the deoxygenation reaction unit; the gas-liquid separation unit serves to separate the gas and liquid phases cooled in the temperature reduction unit; the hydrocarbon separation unit is used to separate at least part of the propylene from the gas phase obtained in the gas-liquid separation unit.

In a preferred embodiment of the present invention, the catalytic oxidation-deoxygenation apparatus is shown in FIG. 1; the device includes a heat exchange unit 1, a heating unit 2, a deoxygenation reaction unit 3, a temperature reduction unit 4, a gas-liquid separation unit 5, and a hydrocarbon separation unit; wherein the heat exchange unit 1 is used to perform heat exchange between the unsaturated hydrocarbon-containing gas A and the gas treated in the deoxygenation reaction unit 3 (also referred to as "deoxygenated gas B") to heat the unsaturated hydrocarbon-containing gas A while cooling the deoxygenated gas B; the heating unit 2 is used for additional heating of the gas containing unsaturated hydrocarbon subjected to heat exchange in the heat exchange unit 1; the deoxygenation reaction unit 3 is used for catalytically oxidizing the unsaturated hydrocarbon-containing gas exiting the heating unit 2 to remove oxygen from the unsaturated hydrocarbon-containing gas; the temperature reduction unit 4 is connected to the heat exchange unit 1 for additional cooling of the deoxygenated gas B heat exchanged in the heat exchange unit 1; the gas-liquid separation unit 5 serves to separate the liquid phase from the gas phase, which is cooled in the temperature reduction unit 4; and the hydrocarbon separation unit is used to separate at least a portion of the hydrocarbons from the gas phase obtained from the gas-liquid separation unit.

In the present invention, the liquid phase separated in the gas-liquid separation unit 5 is considered as waste fluid C; the resulting gas phase is used to separate hydrocarbons and subjected to separation in a hydrocarbon separation unit to obtain unsaturated hydrocarbons E and non-condensable gas D.

According to the present invention, the heat exchange unit 1 is connected to the heating unit 2 for heat exchange between the unsaturated hydrocarbon-containing gas A and the deoxygenated gas B supplied to the heat exchange unit 1; in heat exchange, the unsaturated hydrocarbon-containing gas is heated to promote catalytic oxidation, while the deoxygenated gas B is cooled to facilitate gas-liquid separation.

The present invention does not specifically limit the heat exchange unit 1, as long as the heat exchange effect can be achieved, the heat exchange unit 1 can be an available heat exchanger that can be used for gas heat exchange. For example, a jacket type heat exchanger, a plate heat exchanger, a shell and tube heat exchanger can be used.

The present invention does not particularly limit the heating unit 2, as long as it is capable of heating the unsaturated hydrocarbon-containing gas A to a desired temperature, it may be an available gas heating heater such as an electric heater, a solar heater. The heating unit 2 may be turned on or off as needed, and the heating unit 2 may not be turned on if, after reaching a steady state, the heat generated by the reaction in the deoxygenation reaction unit 3 can enable the post-heat exchange gas in the heat exchange unit 1 to reach the temperature required for the reaction. .

According to the present invention, the deoxygenation reaction unit 3 is used for the catalytic oxidation of an unsaturated hydrocarbon-containing gas to remove oxygen from the unsaturated hydrocarbon-containing gas to obtain deoxygenated gas B. The deoxygenation reaction unit 3 may be an accessible deoxygenation reactor that can be used for catalytic oxidation gaseous hydrocarbon, preferably an adiabatic fixed bed reactor.

According to the present invention, the deoxygenation reaction unit 3, the heat exchange unit 1 and the temperature reduction unit 4 are connected in series, so that the heat exchange unit 1 is capable of exchanging the heat of the deoxygenated gas B with the gas A containing unsaturated hydrocarbon, cooling the deoxygenated gas B to facilitate the next step of gas separation and liquid, and sufficiently utilizing the heat of the deoxygenated gas B to preheat the unsaturated hydrocarbon-containing gas A to accelerate the catalytic deoxygenation reaction.

The temperature reducing unit 4 is not particularly limited in the present invention, as long as it can further cool the deoxygenated gas B to a desired temperature; it can be an available condenser or a heat exchanger that can be used to cool the gas, such as an air condenser.

The gas-liquid separation unit 5 is not particularly limited in the present invention, as long as it can perform separation of the gas phase and the liquid phase obtained by cooling in the temperature reduction unit 4; it can be an accessible container for separating gas and liquid. The gas-liquid separation unit 5 can specifically perform baffle separation, centrifugal separation, packing separation, sieve separation, microporous filter separation, and the like.

The present invention does not particularly limit the hydrocarbon separating unit, as long as it can separate at least a portion of unsaturated hydrocarbons from the gas phase obtained in the gas-liquid separation unit, preferably completely separating unsaturated hydrocarbons. The preferred hydrocarbon separation unit may include a compressor 6 and a non-condensable gas separation column 7, wherein the compressor 6 is used to compress the gas phase obtained from the gas-liquid separation unit so that the unsaturated hydrocarbons contained therein are liquefied; the non-condensable gas separation column 7 is used for separating unsaturated hydrocarbons in a compressed gas phase, in particular, for separating a compressed liquid phase and a gas phase, thereby obtaining liquid unsaturated hydrocarbons E and non-condensable gas D, respectively.

Preferably, in order to facilitate detection of the oxygen removal effect, the deoxygenation reaction apparatus of the present invention is further provided with a residual oxygen analysis (OA) unit for monitoring the oxygen content of the gas phase obtained from the gas-liquid separation unit 5. The residual oxygen analysis unit may be located in the pipeline connecting the gas-liquid separation unit 5 and the hydrocarbon separation unit. Moreover, preferably, the apparatus of the present invention further comprises a feed gas analysis unit for monitoring the oxygen content of the gas supplied to the deoxygenation reaction unit 3, which may be located in the main pipeline supplying the unsaturated hydrocarbon-containing gas.

In the present invention, the residual oxygen analysis unit and the feed gas analysis unit may be analytical measuring devices capable of detecting oxygen concentration in the prior art, such as a magnetic oxygen analyzer, an electrochemical spectrometer for oxygen determination, gas chromatography, a laser spectrometer for oxygen determination, a spectrometer at zirconium dioxide for oxygen determination, cobalt oxide spectrometers for oxygen determination.

According to the present invention, in order to further reduce the oxygen content of the tail gas, at least a portion of the gas phase separated from the gas-liquid mixture is preferably recirculated when the oxygen content of the gas phase separated from the gas-liquid mixture is high, and more preferably, the method further includes recirculating at least a portion of the gas phase separated from the gas-liquid mixture with an unsaturated hydrocarbon-containing gas when the oxygen content of the residual gas in the gas phase separated from the gas-liquid separation is greater than or equal to 0.15%.

In order to carry out the above circulation, the apparatus for carrying out the deoxygenation reaction of the present invention is further provided with a circulation branch pipe connected to an inlet pipe for an unsaturated hydrocarbon-containing gas; the circulation branch pipe serves to return the gas phase obtained from the gas-liquid separation unit 5 to the inlet pipe for the gas containing unsaturated hydrocarbon located upstream of the heat exchange unit 1. The circulation branch pipeline is preferably located in the pipeline connecting the gas separation unit 5 and liquid and the hydrocarbon separation unit is more preferably located downstream of the residual oxygen analysis unit. The circulation branch pipe is additionally preferably provided with a circulation control valve for controlling the circulation volume of the gaseous phase obtained from the gas-liquid separation unit 5 . In addition, the circulation branch pipe can be provided with a blower (eg Roots fan, compressor, exhaust fan) if necessary. By circulating at least a portion of the gas phase obtained from the gas-liquid separation unit 5, it can be effectively ensured that the oxygen removal rate of the deoxygenation reaction apparatus reaches a desired value.

Preferably, the present invention further provides an inlet temperature sensor, an outlet temperature sensor, a feed gas oxygen sensor, and a tail gas oxygen sensor, which detect the feed gas oxygen content, the tail gas oxygen content, the reactor inlet temperature, temperature at the outlet of the reactor, respectively.

According to the present invention, preferably, an inlet control valve is provided on the inlet pipe for supplying the gas containing unsaturated hydrocarbon to the heat exchange unit 1 to control the supply rate of the gas containing unsaturated hydrocarbon; an outlet control valve is provided on the inlet branch pipe to control the amount of discharged gas containing unsaturated hydrocarbon; and a circulation control valve is provided on the circulation branch pipe to control the amount of circulation gas obtained from the gas-liquid separation unit 5.

Further preferably, the method also includes diverting at least a portion of the unsaturated hydrocarbon-containing gas to the combustible gas discharge system, wherein the unsaturated hydrocarbon-containing gas may be diverted to the combustible gas exhaust system via an inlet branch pipe. The inlet branch pipeline may be located on the inlet pipe leading the unsaturated hydrocarbon containing gas to the heat exchange unit 1.

The present invention is described below with reference to examples, but the present invention is not limited to them.

In the following examples, the scanning electron microscope (SEM) is a Hitachi S-4800 cold field emission scanning electron microscope.

The distribution of the content of the active component is analyzed by regional sampling points using a Hitachi S-4800 scanning electron microscope with cold field emission (equipped with an attachment for X-ray energy dispersive spectroscopy (EDS)), namely:

a scanning electron microscope is used, the voltage is set to 5 kV, the cross section of the catalyst is selected, the magnification factor is adjusted, points are taken every 0.2 mm along the radial direction of the catalyst in a clear field of view, for each point the content of the active component, the first component - the shared agent, and the second component is the shared agent.

The analysis of the pore structure of the catalyst was carried out using an ASAP 2020 physical sorption instrument manufactured by Micropericetics Instrument Corporation in the USA, the specific surface area was calculated and determined by the BET method, and the pore size distribution was calculated and determined by the BJH method.

The dispersed size of the catalyst and the content of the corresponding active components in it is measured using a scanning STEM analysis.

Examples 1-4 receive

1) The alumina was first impregnated with an equivalent volume of an aqueous solution containing the active ingredient at pH 4, then dried at 80° C. for 150 minutes;

2) the alumina obtained in step (1) was subjected to a second impregnation with an equivalent volume of an aqueous solution containing component 1, a shared agent selected from the group consisting of rare earth metal oxides, group IVB metal oxides, and group VIII metal oxides, and ethanolamine (with an ethanolamine content of 2 wt.%), at pH 9, then subjected to drying at 130°C for 80 min;

3) the alumina obtained in step (2) was subjected to a third impregnation with an equivalent volume of an aqueous solution containing component 2, a shared agent selected from the group consisting of oxides of alkali metals and oxides of alkaline earth metals, at pH 10, then subjected to drying at 170°C for 100 min, and then subjected to calcination at 500°C for 3 hours to obtain catalytic oxidation catalysts A1-A4, the composition and structure of the catalysts are shown below, the stage conditions are given in table 1.

In FIG. 2 shows an SEM image of the catalytic oxidation catalyst obtained in Production Example 1; in fig. 3 is a graph showing the content distribution of ingredients after impregnation in Production Example 1; in fig. 4 is a graph showing the content distribution of ingredients after impregnation in Production Example 2; in fig. 5 is a graph showing the content distribution of ingredients after impregnation in Production Example 3; and in FIG. 6 is a graph showing the content distribution of ingredients after impregnation in Production Example 4. As shown in FIG. 2-6, along the radial direction from the core of the carrier to the outer surface of the carrier, the content of the active component gradually increases and then gradually decreases, forming a distribution in the form of a peak, the content of component 1 - the joint agent gradually increases, and then gradually decreases, forming a distribution in the form of peak, the content of component 2 - shared agent gradually increases, and the peak value of the content of the active component is 0.2 mass. % or more.

Comparative Example 1 Receipt

Catalysts were obtained in the same manner as in Production Example 1, except that the impregnation with component 1, a shared agent, was not carried out, catalyst D1 was obtained, the composition and structure of the catalysts are shown below.

In FIG. 7 shows an SEM image of the catalytic oxidation catalyst obtained in Comparative Production Example 1; in fig. 8 is a graph showing the content distribution of ingredients after impregnation in Comparative Production Example 1; as shown in FIG. 7-8, along the radial direction from the core of the carrier to the outer surface of the carrier, the content of the active ingredient gradually increases and then gradually decreases, forming a distribution in the form of a peak, the content of component 2 - the joint agent gradually increases, and the peak value of the content of the active ingredient is 0, 2 wt. % or more.

Comparative Example 2 Receipt

Catalysts were obtained in the same manner as in Production Example 1, except that the impregnation with the component 2-co-agent was not carried out, catalyst D2 was obtained, the composition and structure of the catalysts are shown below.

In FIG. 9 shows an SEM image of the catalytic oxidation catalyst obtained in Comparative Production Example 2; in fig. 10 is a graph showing the content distribution of ingredients after impregnation in Comparative Production Example 2; as shown in FIG. 9-10, along the radial direction from the core of the carrier to the outer surface of the carrier, the content of the active component gradually increases and then gradually decreases, forming a distribution in the form of a peak, the content of component 1 - the joint agent gradually increases, and then gradually decreases, forming a distribution in the form peak, and the peak value of the content of the active component is 0.2 mass. % or more.

Comparative Example 3 Receive

The alumina was impregnated with an equivalent volume of an aqueous solution containing the active ingredient, component 1 - shared agent, component 2 - shared agent and ethanolamine, at pH 4, then subjected to drying at 80°C for 150 min, and then subjected to calcination at 500°C for 3 hours to obtain a catalytic oxidation catalyst D3, the composition and structure of which are shown below.

In FIG. 11 shows an SEM image of the catalytic oxidation catalyst obtained in Comparative Production Example 3; in fig. 12 is a graph showing the content distribution of ingredients after impregnation in Comparative Production Example 3; as shown in FIG. 11-12, along the radial direction from the core of the carrier to the outer surface of the carrier, the content of the active component gradually increases and then gradually decreases, forming a distribution in the form of a peak, the content of component 1 - the joint agent gradually increases, and then gradually decreases, forming a distribution in the form peak, the content of component 2 - shared agent gradually increases, but the peak value of the content of the active component is less than 0.2 mass. %.

Comparative Example 4 Receipt

Catalysts were obtained in the same manner as in Preparation Example 1, except that the impregnation was not carried out in stages, but the alumina was impregnated with an equivalent volume of an aqueous solution containing the active ingredient, component 1 is a shared agent, component 2 is a shared agent and ethanolamine, at pH 9, then subjected to drying at 80°C for 150 minutes, and then subjected to calcination at 500°C for 3 hours to obtain a catalytic oxidation catalyst D4, the composition and structure of the catalyst are shown below.

In FIG. 13 shows an SEM image of the catalytic oxidation catalyst obtained in Comparative Production Example 4; in fig. 14 is a graph showing the content distribution of ingredients after impregnation in Comparative Production Example 4; as shown in FIG. 13-14, along the radial direction from the core of the carrier to the outer surface of the carrier, the content of the active component gradually increases and then gradually decreases, forming a distribution in the form of a peak, the content of component 1 - the joint agent gradually increases, and then gradually decreases, forming a distribution in the form peak, the content of component 2 - shared agent gradually increases, but the peak value of the content of the active component is less than 0.2 mass. %.

Receiving Comparative Example 5

Catalysts were prepared in the same manner as in Production Example 1, except that the impregnation process was carried out in two steps. In the first step, alumina was subjected to a first impregnation with an equivalent volume of an aqueous solution containing the active ingredient, component 1 - co-agent and ethanolamine, at pH 9, and then subjected to drying at 130° C. for 80 minutes; in the second step, the alumina obtained after the first impregnation with an equivalent volume was subsequently subjected to a second impregnation with an equivalent volume of an aqueous solution containing component 2, a co-agent selected from the group consisting of oxides of alkali metals and oxides of alkaline earth metals, at pH 10, and subjected to drying at 170°C for 100 minutes, and then subjected to calcination at 500°C for 3 hours to obtain a catalytic oxidation catalyst D5, the composition and structure of which are shown below.

In FIG. 15 shows an SEM image of the catalytic oxidation catalyst obtained in Comparative Production Example 5; in fig. 16 is a graph showing the content distribution of ingredients after impregnation in Comparative Production Example 5; as shown in FIG. 15-16, along the radial direction from the core of the carrier to the outer surface of the carrier, the content of the active component gradually increases and then gradually decreases, forming a distribution in the form of a peak, the content of component 1 - the joint agent gradually increases, and then gradually decreases, forming a distribution in the form peak, the content of component 2 - shared agent gradually increases, but the peak value of the content of the active component is less than 0.2 mass. %.

Catalyst A1: a catalyst containing 0.25 wt. % palladium oxide (in terms of the metal element Pd), 0.1 wt. % ferric oxide, 5.67 wt. % sodium oxide, and the rest is the carrier - alumina; the catalyst has a specific surface area of 230 m ² /g and a pore volume of 0.5 cm ³ /g; mesopores with a pore size of more than 2 nm and 50 nm or less account for 28% of the total pore volume, and macropores with a pore size of more than 50 nm and 200 nm or less account for 70% of the total pore volume; the active component, having a dispersed size of less than 10 nm, is contained in an amount of 93 wt. % of the total active component in the catalyst.

Catalyst D1: a catalyst containing 0.25 wt. % palladium oxide (in terms of the metal element Pd), 5.67 wt. % sodium oxide, and the rest is the carrier - alumina; the catalyst has a specific surface area of 265 m ² /g and a pore volume of 0.65 cm ³ /g; mesopores with a pore size of more than 2 nm and 50 nm or less account for 45% of the total pore volume, and macropores with a pore size of more than 50 nm and 200 nm or less account for 53% of the total pore volume; the active component, having a dispersed size of less than 10 nm, is contained in an amount of 25 wt. % of the total active component in the catalyst.

Catalyst D2: a catalyst containing 0.25 wt. % palladium oxide (in terms of the metal element Pd), 0.1 wt. % ferric oxide, and the rest is the carrier - alumina; the catalyst has a specific surface area of 225 m ² /g and a pore volume of 0.55 cm ³ /g; mesopores with a pore size of more than 2 nm and 50 nm or less account for 30% of the total pore volume, and macropores with a pore size of more than 50 nm and 200 nm or less account for 68% of the total pore volume; the active component having a dispersed size of less than 10 nm is contained in an amount of 45 wt. % of the total active component in the catalyst.

Catalyst D3: a catalyst containing 0.25 wt. % palladium oxide (in terms of the metal element Pd), 0.1 wt. % ferric oxide, 5.67 wt. % sodium oxide, and the remainder is a carrier - alumina; the catalyst has a specific surface area of 72 m ² /g and a pore volume of 0.5 cm ³ /g; mesopores with a pore size of more than 2 nm and 50 nm or less account for 10% of the total pore volume, and macropores with a pore size of more than 50 nm and 200 nm or less account for 87% of the total pore volume; the active component, having a disperse size of less than 10 nm, is contained in an amount of 18.5 wt. % of the total active component in the catalyst.

Catalyst D4: a catalyst containing 0.25 wt. % palladium oxide (in terms of the metal element Pd), 0.1 wt. % ferric oxide, 5.67 wt. % sodium oxide, and the rest is the carrier - alumina; the catalyst has a specific surface area of 62 m ² /g and a pore volume of 0.75 cm ³ /g; mesopores with a pore size of more than 2 nm and 50 nm or less account for 1.5% of the total pore volume, and macropores with a pore size of more than 50 nm and 200 nm or less account for 97% of the total pore volume; the active component, having a dispersed size of less than 10 nm, is contained in an amount of 6 wt. % of the total active component in the catalyst.

Catalyst D5: a catalyst containing 0.25 wt. % palladium oxide (in terms of the metal element Pd), 0.1 wt. % ferric oxide, 5.67 wt. % sodium oxide, and the rest is the carrier - alumina; the catalyst has a specific surface area of 68 m ² /g and a pore volume of 0.73 cm ³ /g; mesopores with a pore size of more than 2 nm and 50 nm or less account for 3.8% of the total pore volume, and macropores with a pore size of more than 50 nm and 200 nm or less account for 95% of the total pore volume; the active component having a dispersed size of less than 10 nm is contained in an amount of 9 wt. % of the total active component in the catalyst.

Catalyst A2: a catalyst containing 0.2 wt. % palladium oxide (in terms of the metal element Pd), 0.3 wt. % cobalt oxide, 4.89 wt. % sodium oxide, and the rest is a carrier - alumina; the catalyst has a specific surface area of 195 m ² /g and a pore volume of 0.52 cm ³ /g; mesopores with a pore size of more than 2 nm and 50 nm or less account for 10% of the total pore volume, and macropores with a pore size of more than 50 nm and 200 nm or less account for 60% of the total pore volume; the active component, having a dispersed size of less than 10 nm, is contained in an amount of 95 wt. % of the total active component in the catalyst.

Catalyst A3: a catalyst containing 0.5 wt. % ruthenium oxide (in terms of the metal element Ru), 0.7 wt. % titanium dioxide, 4.89 wt. % magnesium oxide, and the rest is a carrier - alumina; the catalyst has a specific surface area of 230 m ² /g and a pore volume of 0.5 cm ³ /g; mesopores with a pore size of more than 2 nm and 50 nm or less account for 5% of the total pore volume, and macropores with a pore size of more than 50 nm and 200 nm or less account for 80% of the total pore volume; the active component, having a dispersed size of less than 10 nm, is contained in an amount of 96 wt. % of the total active component in the catalyst.

Catalyst A4: a catalyst containing 0.5 wt. % rhodium oxide (in terms of the metallic element Rh), 0.7 wt. % titanium dioxide, 4.89 wt. % potassium oxide, and the rest is a carrier - alumina; the catalyst has a specific surface area of 230 m ² /g and a pore volume of 0.5 cm ³ /g; mesopores with a pore size of more than 2 nm and 50 nm or less account for 20% of the total pore volume, and macropores with a pore size of more than 50 nm and 200 nm or less account for 70% of the total pore volume; the active component, having a dispersed size of less than 10 nm, is contained in an amount of 96 wt. % of the total active component in the catalyst.

Test Example 1 The mass percentage of carbon deposits for catalysts A1-A4 and D1-D5 was measured in a propylene atmosphere at a pressure of 0.6 MPa at a temperature of 573.15 K after a reaction time of 100 hours, 1000 hours and 2000 hours, respectively, where the catalyst was used in an amount of 20 g per 1 mol of propylene, and the results for carbon deposits on the catalyst are shown in table 2.

Test Example 2 Catalysts A1-A4, D1-D5 were subjected to reduction with hydrogen gas at normal pressure and a temperature of 473.15 K for 10 hours, the amount of adsorbed oxygen at saturation for catalysts A1-A4 after the reduction process was measured at temperatures of 323.15 K, 423.15 K and 623.15 K, respectively, the results are shown in Table 3. The method for measuring the amount of adsorbed oxygen at saturation was as follows: a chemisorption device and a mass spectrometer were used together (Autochem 2910 chemisorption device, OmniStar mass spectrometer) , the sample was weighed in an amount of 0.1 g, subjected to reduction with hydrogen gas (a mixture of gases of 10 vol.% hydrogen gas and argon gas) at 200 ° C for 2 hours, the heating rate was 10 ° C / min, then the sample was subjected to purging high purity helium gas at 200°C for 0.5 hour, then the temperature was reduced to 50°C (100°C, 150°C), after stabilization of the baseline purge oxygen (gas mixture 5 vol. % oxygen and helium gas) were used to carry out pulsed chemisorption to adsorption saturation state, and quantitative calculation of the adsorption amount was performed to obtain the amount of adsorbed oxygen per gram of catalyst at various temperatures. The ambient pressure in the experiments was atmospheric.

Example 1

The treatment of the propylene tail gas was carried out using a catalytic oxidation-deoxygenation device containing an unsaturated hydrocarbon gas, as shown in FIG. 1, propylene tail gas consisted of 8 vol. % oxygen, 90 vol. % propylene and 2 vol. % nitrogen.

The catalytic oxidation-deoxygenation apparatus included a heat exchange unit 1, a heating unit 2, a deoxygenation reaction unit 3, a temperature reduction unit 4, a gas-liquid separation unit 5, and a hydrocarbon separation unit; wherein the heat exchange unit 1 was a heat exchanger for exchanging heat between the unsaturated hydrocarbon-containing gas and the gas treated in the deoxygenation reaction unit; the heating unit 2 was an electric heater for post-heating the unsaturated hydrocarbon-containing gas after heat exchange in the heat exchange unit 1. The deoxygenation reaction unit 3 was a fixed-bed adiabatic reactor which was provided with a bed of catalytic oxidation catalyst A1 to catalytically oxidize the unsaturated hydrocarbon containing gas from the heating unit 2, remove oxygen from the unsaturated hydrocarbon-containing gas, resulting in deoxygenated gas B; the temperature reduction unit 4 was an air condenser connected to the heat exchange unit 1 to further cool the deoxygenated gas B; the gas-liquid separation unit 5 was a gas-liquid separation vessel for separating the liquid phase from the gas phase, which is cooled in the temperature reduction unit 4; the hydrocarbon separation unit consisted of a compressor 6 and a non-condensable gas separation column 7 for separating at least a portion of the propylene from the gas phase obtained from the gas-liquid separation unit; in the pipeline connecting the gas-liquid separation unit 5 and the compressor 6, a residual oxygen analysis unit is placed to control the oxygen content in the gas phase obtained from the gas-liquid separation unit 5.

The device was additionally provided with a circulation branch pipe, which was placed downstream of the residual oxygen analysis unit of the pipeline connecting the gas-liquid separation unit 5 and the hydrocarbon separation unit, and was connected to the inlet pipeline for the gas containing unsaturated hydrocarbon, which was used to return the gas the phase obtained from the gas-liquid separation unit 5 into the inlet pipeline for the gas containing unsaturated hydrocarbon located in front of the heat exchange unit 1; the circulation branch pipe was provided with a circulation control valve.

The propylene tail gas at a temperature of 40°C was fed into the catalytic oxidation-deoxygenation device and heated in the heat exchanger to 110°C (i.e., the reactor inlet temperature), the propylene tail gas was fed into the deoxygenation reactor to carry out the catalytic oxidation-deoxygenation reaction at an hourly space velocity of 10,000 h ^-1 , a reaction pressure of 10 MPa, a linear velocity of 0.02 m/s, a pressure-line velocity product of 0.2 MPa⋅m/s, and a reactor outlet temperature of 280°C, to obtain a deoxygenated gas B.

The deoxygenated gas B was heat exchanged with the original propylene tail gas and heated to 80°C and then cooled in an air condenser to 20°C, and it subsequently entered a gas-liquid separation vessel, in which the liquid phase formed during the reaction was separated. process, as waste fluid C, and the separated gas phase had an oxygen content in the residual gas of 0.10 vol. %, selectivity for CO was 0.5%, and selectivity for CO ₂ was 99.1%. The gas phase was pressurized by the compressor 6, and then the gas phase was introduced into the non-condensable gas separation column 7, the separated gas phase was non-condensable gas D, and the separated liquid phase was propylene (99.5% purity or higher). Non-condensable gas D consisted of 50.3 vol. % nitrogen gas, 49.5 vol. % CO ₂ and 0.2 vol. % CO.

The amount of carbon deposits on the catalyst, as measured, was 1.2% after 1000 hours from the start of the reaction, 2.1% after 2000 hours, 2.9% after 3000 hours, 4.1% after 5000 hours, 5.8% after 8000 hours. After 15060 hours, the oxygen content of the residual gas in the separated gas phase was measured to be 0.28 vol. %, the amount of carbon deposits was 9.8%, indicating the deactivation of the catalyst, the reaction device was stopped, and it was necessary to burn the carbon deposits and regenerate the catalyst.

Example 2

The treatment of the propyne tail gas was carried out using a catalytic oxidation-deoxygenation device containing an unsaturated hydrocarbon gas, as shown in FIG. 1, the catalyst is A2 catalytic oxidation catalyst.

Propyne residual gas consisted of 7 vol. % oxygen, 88 vol. % propyne and 3 vol. % nitrogen. Propyne residue gas at 40°C was introduced into the catalytic oxidation-deoxygenation device and heated in a heat exchanger to 200°C (i.e. reactor inlet temperature), propine residue gas was fed into the deoxygenation reactor to carry out the catalytic oxidation-deoxygenation reaction at an hourly space velocity of 5000 h ⁻¹ , a pressure of 5 MPa, a linear velocity of 0.2 m/s, a product of pressure and a linear velocity of 1 MPa⋅m/s, and a reactor outlet temperature of 350° C., to obtain deoxygenated B2 gas.

The deoxygenated gas B2 was subjected to heat exchange with the initial propyne tail gas and heated to 110°C and then cooled by an air condenser to 20°C, and subsequently it entered the gas-liquid separation vessel, in which the liquid phase obtained during the reaction was separated. process, as waste fluid C, and the separated gas phase had an oxygen content in the tail gas of 0.13 vol. %, selectivity for CO was 0.06%, and selectivity for CO ₂ was 99.0%. The gas phase was pressurized with a compressor, and then the gas phase was introduced into a non-condensable gas separation column, the separated gas phase was a non-condensable gas, and the separated liquid phase was propyne (99.6% purity or higher). The non-condensable gas consisted of 5.8 vol. % nitrogen gas, 94 vol. % CO ₂ and 0.2 vol. % CO.

The amount of carbon deposits on the catalyst was measured to be 1.3% at 1000 hours, 2.0% at 2000 hours, 3.1% at 3000 hours, 4.6% at 5000 hours, 6.2% at 8000 hours from the start of the reaction. After 16100 hours of reaction, the oxygen content of the tail gas in the separated gas phase was measured to be 0.28 vol. %, the amount of carbon deposits was 10.5%, indicating the deactivation of the catalyst, the reaction device was stopped, and it was necessary to burn the carbon deposits and regenerate the catalyst.

Example 3

The catalytic oxidation-deoxygenation was carried out in accordance with the same method as in Example 1, except that the catalytic oxidation catalyst A3 was used as the catalyst, the reaction space rate was 500 h ^-1 , the pressure was 0.4 MPa, the linear velocity was 5 m/s, the product of pressure and linear velocity was 2 MPa⋅m/s. The amount of carbon deposits on the catalyst was measured to be 1.0% at 1000 hours, 1.8% at 2000 hours, 2.7% at 3000 hours, 3.9% at 5000 hours, 5.85% at 8000 hours from the start of the reaction. After 17500 hours of reaction, the oxygen content of the tail gas in the separated gas phase was measured to be 0.28 vol. %, the amount of carbon deposits was 11.9%, indicating the deactivation of the catalyst, the reaction device was stopped, and it was necessary to burn the carbon deposits and regenerate the catalyst.

Example 4

Catalytic oxidation-deoxygenation was carried out in accordance with the same method as in Example 1, except that A4 catalytic oxidation catalyst was used as the catalyst, and the line speed was 0.5 m/s. The amount of carbon deposits on the catalyst was measured to be 1.25% at 1000 hours, 2.0% at 2000 hours, 2.85% at 3000 hours, 4.7% at 5000 hours, 7.1% at 8000 hours from the start of the reaction. After 14500 hours of reaction, the oxygen content of the tail gas in the separated gas phase was measured to be 0.28 vol. %, the amount of carbon deposits was 11%, indicating the deactivation of the catalyst, the reaction device was stopped, and it was necessary to burn the carbon deposits and regenerate the catalyst.

Comparative Example 1 Catalytic oxidation-deoxygenation was carried out according to the same method as in Example 1, except that the line speed was 0.01 m/s, the product of pressure and line speed was 0.1 MPa⋅m/s , and the amount of carbon deposits on the catalyst, as measured, was 16% after 1000 hours from the start of the reaction.

Comparative Example 2 Catalytic oxidation-deoxygenation was carried out according to the same method as in Example 1, except that the linear velocity was 11 m/s, the product of pressure and linear velocity was 55 MPa⋅m/s, and the amount of carbon deposits on the catalyst, as measured, was 12% after 1000 hours from the start of the reaction.

Comparative Example 3 Catalytic oxidation-deoxygenation was carried out according to the same method as in Example 1, except that the pressure was 21 MPa, the pressure-line velocity product was 0.42 MPa⋅m/s, and the amount of carbon deposits on the catalyst, as measured, was 15% after 1000 hours from the start of the reaction.

Comparative Example 4 Catalytic oxidation-deoxygenation was carried out in accordance with the same method as in Example 1, except that catalyst A1 was replaced by catalyst D1, and the amount of carbon deposits on the catalyst was measured to be 4.5% through 1000 h from the start of the reaction.

Comparative Example 5 Catalytic oxidation-deoxygenation was carried out in accordance with the same method as in Example 1, except that Catalyst A1 was replaced by Catalyst D2, and the amount of carbon deposits on the catalyst was measured to be 3.6% through 1000 h from the start of the reaction.

Comparative Example 6 Catalytic oxidation-deoxygenation was carried out in accordance with the same method as in Example 1, except that Catalyst A1 was replaced by Catalyst D3, and the amount of carbon deposits on the catalyst was measured to be 6.8% through 1000 h from the start of the reaction.

Comparative Example 7 Catalytic oxidation-deoxygenation was carried out in accordance with the same method as in Example 1, except that Catalyst A1 was replaced by Catalyst D4, and the amount of carbon deposits on the catalyst was measured to be 9.1% through 1000 h from the start of the reaction.

Comparative Example 8 Catalytic oxidation-deoxygenation was carried out in accordance with the same method as in Example 1, except that Catalyst A1 was replaced by Catalyst D5, and the amount of carbon deposits on the catalyst was measured to be 10.2% through 1000 h from the start of the reaction.

The above description, in conjunction with the accompanying drawings, describes in detail the preferred embodiments of the present invention, but the present invention is not limited to them. Various simple modifications can be implemented in relation to the technical solutions of the present invention within the technical concept of the present invention, including the combination of individual technical features in any suitable way. Possible combinations of various technical features are not further described in the present invention in order to avoid unnecessary repetition. However, such simple modifications and combinations thereof should also be considered as content described in the present invention, each of which falls within the protection scope of the present invention.

Claims (32)

1. An oxidation-deoxygenation catalyst containing an unsaturated hydrocarbon gas containing a carrier, as well as an active component, the first component is a shared agent and the second component is a shared agent deposited on the carrier, where the active component is one or more components selected from the group , consisting of oxides of Pt, Pd, Ru, Rh, Ag and Ir; the first component, the shared agent, includes one or more elements selected from the group consisting of a rare earth metal, a metal of group IVB, and a metal of group VIII, and the second component, a shared agent, includes one or more elements selected from the group consisting of an alkali metal and alkaline earth metal; in the radial direction from the core of the carrier to the outer surface of the carrier, the content of the specified active component gradually increases and then gradually decreases to form a distribution in the form of a peak, the content of the specified first component - the joint agent gradually increases and then gradually decreases to form a distribution in the form of a peak, the content of the specified second component - shared agent gradually increases, and the peak value of the content of the specified active component is 0.2 mass. % or more; the specified active ingredient is contained in an amount of 0.05-2 wt. % in terms of the metal element, the specified first component - a shared agent is contained in an amount of 0.1-3 wt. % in terms of oxide, and the specified second component - a shared agent is contained in an amount of 1-7 wt. % in terms of oxide, based on the dry weight of the catalyst. 2. The catalyst according to claim 1, wherein the mass percentage of carbon deposits y for the catalyst, measured in a propylene atmosphere at a pressure of 0.6 MPa and a temperature of 573.15 K, has the following characteristics: y=0.9y1 - 1.1y1, y1=(-0.0029+0.3748×t ^0.3013 )/100, where t is the reaction time, in the range of 100-2000 hours; moreover, before the measurement, the catalyst has a mass percentage of carbon deposits of 0.2% or less; preferably, the amount q of adsorbed oxygen at saturation for the catalyst after reduction with hydrogen at normal pressure and temperature of 473.15 K has the following characteristics: q=0.8q1 - 1.2q1, q1=a+b×T ^c +d×T ^e , where q is the amount of adsorbed oxygen at saturation, ml/g; T - adsorption temperature, in the range of 323.15-623.15 K; a=-0.0685; b=7.016×10 ^-6 ; c=2.06; d=-5.83×10 ^-8 ; e=2.76. 3. The catalyst according to claim 1 or 2, wherein the first component, the shared agent, comprises one or more elements selected from the group consisting of a Group IVB metal and a Group VIII metal, and the second component, the shared agent, comprises an alkali metal; more preferably, the first shared agent component is one or more selected from the group consisting of ferric oxide, cobalt oxide, nickel oxide, and titanium oxide, and the second shared agent component is sodium oxide; even more preferably, the weight ratio of the first component - shared agent to the second component - shared agent is 1:20-220, preferably 1:60-200. 4. The catalyst according to any one of paragraphs. 1-3, which has a specific surface area of 100-260 m ² /g and a pore volume of 0.2-0.7 cm ³ /g; mesopores with a pore size of more than 2 nm and 50 nm or less make up 2-40%, preferably 5-30% of the total pore volume, and macropores with a pore size of more than 50 nm and 200 nm or less make up 50-90%, preferably 60- 80% of the total pore volume; preferably, the catalyst carrier is one or more carriers selected from the group consisting of alumina, silica, titanium dioxide, molecular sieves and carbon nanotubes. 5. The catalyst according to any one of paragraphs. 1-4, in which the content of the active component having a disperse size of less than 10 nm is 80 wt. % or more of the total active ingredient. 6. A method for catalytically oxidizing-deoxygenating an unsaturated hydrocarbon-containing gas comprising an unsaturated hydrocarbon and oxygen, comprising contacting an unsaturated hydrocarbon-containing gas with a catalyst and performing a catalytic oxidation process to remove oxygen from the unsaturated hydrocarbon-containing gas; where the catalyst is the specified catalyst according to any one of paragraphs. 1-5, the contacting conditions include that the unsaturated hydrocarbon-containing gas has an hourly space velocity of 200-50000 h ^-1 , preferably 200-20000 h ^-1 , a pressure of 0.01-20 MPa, a linear velocity of 0.02-10 m/s, and the product of pressure and linear velocity is 0.1-5 MPa⋅m/s. 7. The method of catalytic oxidation-deoxygenation according to claim 6, in which the gas containing unsaturated hydrocarbon has an hourly space velocity of 500-20000 h ^-1 , preferably 500-10000 h ^-1 , pressure of 0.4-10 MPa, linear velocity of 0.02 -5 m/s, and the product of pressure and linear velocity is 0.2-5 MPa⋅m/s. 8. The catalytic oxidation-deoxygenation process according to claim 6 or 7, which further comprises the following steps: (1) lowering the temperature of the gas obtained from the catalytic oxidation reaction and separating the gas and liquid; (2) separating the gas phase resulting from the gas-liquid separation to obtain at least a portion of the unsaturated hydrocarbons. 9. The method of catalytic oxidation-deoxygenation according to any one of paragraphs. 6-8, which further includes, prior to the catalytic oxidation, exchanging heat between the unsaturated hydrocarbon-containing gas and the gas resulting from the catalytic oxidation reaction. 10. The method of catalytic oxidation-deoxygenation according to any one of paragraphs. 6-9, wherein the unsaturated hydrocarbons are unsaturated hydrocarbons with C4 or less carbon atoms, preferably one or more unsaturated hydrocarbons selected from the group consisting of ethylene, propylene, 1-butene, 2-butene, isobutylene, 1, 3-butadiene, acetylene, propyne, 1-butyne and 2-butyne. 11. The method of catalytic oxidation-deoxygenation according to any one of paragraphs. 6-10, in which the temperature at the inlet to the reactor is 60-400°C, the temperature at the outlet of the reactor is 100-600°C; preferably, the temperature at the inlet to the reactor is 100-380°C, the temperature at the outlet of the reactor is 150-550°C; preferably, said catalytic oxidation reaction is carried out in a fixed bed reactor. 12. The method of catalytic oxidation-deoxygenation according to any one of paragraphs. 6-11, which further includes a safety control process including a block-trigger alarm step, wherein the lock-trigger alarm step includes determining whether the reactor inlet temperature, the reactor outlet temperature, the oxygen content of the feed gas have reached , the oxygen content of the residual gas of the corresponding alarm value or blocking value, and the implementation of emergency blocking control; preferably, the lower reactor inlet temperature alarm value is 60-90°C, the reactor inlet temperature lower shutdown value is 40-60°C, the reactor outlet temperature upper alarm value is 580-610°C, the upper reactor temperature at the outlet of the reactor is 610-650°C, the upper emergency value of the oxygen content in the feed gas is 7.5-8.5 vol. %, the upper blocking value of the oxygen content in the supplied gas is 8.5-10 vol. %, and the upper emergency value of the oxygen content in the residual gas is 0.2-0.3 vol. %. 13. The method of catalytic oxidation-deoxygenation according to any one of paragraphs. 6-12, in which the gas containing unsaturated hydrocarbon contains 0.2-8% oxygen and 5-99% unsaturated hydrocarbons in terms of volume percentage concentration.